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United States Patent | 5,527,074 |
Yeh | June 18, 1996 |
Disclosed is a door lock for locking a double-swinging type fire protection door. The door lock has a safety device controlled by a melting heat sensitive element to lock the spring bolt of the lock bolt in the locked position when the ambient temperature is sharply increased due to a fire.
Inventors: | Yeh; Wen Tien (No. 1-6, Ta Lee Street, Taipei, TW) |
Appl. No.: | 327139 |
Filed: | October 20, 1994 |
Current U.S. Class: | 292/177; 292/21; 292/34; 292/92; 292/DIG.62; 292/DIG.66 |
Intern'l Class: | E05C 001/02 |
Field of Search: | 292/166,168,174,332,333,DIG. 66,140,DIG. 21,46 |
4005886 | Feb., 1977 | Lirette | 292/DIG. |
4099292 | Jul., 1978 | McCabe | 292/DIG. |
4099753 | Jul., 1978 | Gwozdz et al. | 292/DIG. |
4145900 | Mar., 1979 | Ohno | 292/DIG. |
4445717 | May., 1984 | Imhoff | 292/DIG. |